1. Field of the Invention
The present invention relates to a search method for searching a target address on a disc loaded in a disc player system.
2. Description of Background Information
Disc player systems for playing an information recording disc (simply referred to as a disc) on which an information signal such as the video format signal or the audio signal is recorded with address data in a track form, a pickup for retrieving the information signal from the track is carried by a slider which is movable in a direction of a disc radius. In those disc players, address data, such as the frame number, the block number, the chapter number, and playing time from a standard point to the pickup position on the track, i.e. the positional information, is read out and a comparison is performed between the present address of the data block under playing and a target address of a target data block from which the playing is to be started.
As an example of the method of searching address data, a method is disclosed in Japanese Patent Application Laid Open No. 58-62868. In this conventional method, the pickup is moved to the vicinity of a target address by the so-called scanning operation while the speed of movement of the slider in radial direction, i.e., the scanning speed, is adjusted in accordance with comparison between the address data obtained from the pickup and data of the target address.
In the case of the above-described conventional method of searching address data, it is necessary that the scanning speed is lower than a speed at which the address data can be read in order, and the time required for searching becomes long when the difference between the present address and the target address is large. Hence, random access operations were not always performed rapidly with this conventional method.
On the other hand, when the slider is moved at high speeds, the inertial force of the slider increases. As a result, in the case of a slider having a low frictional resistance such as a slider using a linear motor, the slider does not stop immediately when a driving output to a slider motor is stopped or when a braking force is applied to the slider. This is inconvenient since the slider will stop at a position beyond the target address.